Jacks define female electrical connectors having a non-conductive housing and electrical conductive terminals therein. The jack typically is mounted to a circuit board, panel or the like, with the terminals in the jack being electrically connected to conductive areas on the circuit board or panel. The jack is mateable with a male plug connector which also has a nonconductive housing and a corresponding number of electrically conductive terminals. The plug frequently will be mounted to a cable having a plurality of electrically conductive leads which are respectively connected to the terminals in the plug. The cable leading to the plug may define a round cable or a flat flexible cable depending upon the particular application.
The combination of jacks and mateable plugs are used in many electrical devices, with broad applications being found in computers and telecommunications equipment. In most such applications it is necessary to shield signal-carrying circuits to avoid generating electromagnetic interference (EMI), and/or to avoid being impacted by ambient EMI. In particular, the signal carrying cables leading to the above described plug typically will include an electrically conductive shield, such as a braid or foil, extending around the signal carrying conductors of the cable. The plug to which the cable is connected also may include an electrically conductive shield extending thereabout and in electrical contact with the shield of the cable.
The jack will include its own shield which will be grounded to the board on which the jack is mounted. The typical shield for the prior art jack is mounted to the exterior of the jack housing, and has solder tails or other such board contact means unitary therewith and disposed to be electrically connected to grounds on the board. The shield of the prior art jack includes contact means extending into the plug-receiving cavity of the jack. The contact means of the shield for the prior art jack are disposed to electrically contact the shield of the above-described plug.
Many jacks have standard configurations and dimensions within various industries. One type of shielded jack is "box" or rectangularly shaped and includes a rectangularly shaped dielectric housing having a front face, a bottom board mounting wall, and a top, a rear and a pair of side walls substantially surrounding the plug-receiving cavity which extends rearwardly from the front face for receiving the mating plug. Although shields have been fabricated by a plurality of parts, it has become widely accepted to provide the shield as a one-piece, substantially rectangular component stamped and formed of sheet metal material and having front, top, rear and side wall portions substantially surrounding and shielding the front face and the top, rear and side walls of the dielectric housing. Examples of these types of "box" or rectangularly shaped jacks are shown in U.S. Pat. Nos. 4,679,879; 4,878,858; 5,083,945 and 5,195,911, all of which are assigned to the assignee of the present invention.
One of the problems that has affected the design of such shielded jacks for many years is the miniaturization that continue to be demanded in the computer and telecommunications industries. Continuing miniaturization and greater circuit density demands that electrical connectors, including shielded jacks, provide a low profile on the circuit board. Even small reductions in a connector's or jack's profile are greeted with significant commercial success. Particularly desirable are connectors or jacks which can provide a lower profile while still being mateable with an accepted and standardized plug connector.
One area in which the height profile of a jack is affected involves mounting the rectangular shield about the rectangular dielectric housing. Surrounding the front, rear, top and side walls of the housing with a thickness of the shield practically has become a given parameter. However, attempts have been made to eliminate the thickness (i.e. height) of the shield at the bottom board mounting wall of the jack housing. Portions of the shield usually must be folded under the housing to maintain structural stability for the shield. For instance, such stability is necessary to keep the shield side walls from opening up from the bottom. However, the existence of flaps or tabs beneath the housing increases the height profile of the jack. Attempts have been made to insert the flaps or tabs into slots in the housing above the bottom board mounting wall thereof, but these attempts have proven difficult to achieve during assembly, without involving expensive assembly operations.
This invention is directed to solving those problems by providing improvements wherein the shield is mounted about the jack housing in a very simple and efficient manner without any portions of the shield projecting below the bottom mounting wall of the jack housing.